ObjectiveTo diagnose tubal pathology various diagnostic tests are available. Hysterosalpingography (HSG) and diagnostic laparoscopy are established invasive tests. Recently, transvaginal hydrolaparoscopy (THL) was developed. THL has the advantage of direct visualisation of the tubes, but in contrast to diagnostic laparoscopy, the procedure can be performed in an outpatient setting. Although THL seems promising, it is unclear what its effectiveness and costs are relative to the current best imaging strategy, HSG.The purpose of this study is to assess the costs and effects of THL compared to HSG in a large randomized controlled trial.

Power/data analysisThe analysis will be by intention to treat, using a non-inferiority approach. If THL results in equivalent live birth rates, and has lower costs and less burden to women, this will be the preferred strategy. Assuming a pregnancy rate of 70% after 12 months in both groups, the inclusion of 665 women per arm (total 1330) will allow us to exclude a difference larger than 6% in favour of the HSG strategy (alpha .05, beta .80).

Economic evaluationThe economic evaluation will be performed alongside the randomized controlled trial, using a societal perspective. Considering the non-inferiority design, if a strategy using THL is confirmed to be at least as effective as HSG followed by DLS, we will perform a cost-minimisation analysis. If this CMA indicates that societal costs associated with THL are higher than for HSG, the economic evaluation will be extended with a cost-effectiveness, to evaluate whether a shorter time to live-birth outweighs the incremental costs. The question will be whether these extra costs are acceptable to realize this health benefit.